Fly-screen for windows



M. H. BLAISDBLL. FLY SCREEN FOR WINDOWS,.DO0RS,

(No Mode@y ANo. 532,439. Pa'tented Jan. l5, 1895.

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Wala/ZIM d UNITED vSTATES PATENT OFFICE.

MARY HALL ELAI'sDELVL, oELEw1sToN-,MAINE- FLY-SCREEN FOR WINDOWS,DOORS', 84C.

SPECIFICATION forming part of Letters Patent No. 582,439, dated January15, 1895. Application tiled April 23, 1894. Serial No. 508,590. (Nomodel.)

`dows, Doors, &c.; and I do hereby declare the following to be afull,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to improvements in window and door screens used forthe exclusion of flies and ings, &c.

The object of the invention is to take advantage of the well-knowndesire of insects to crawl upward and to provide them with an exit frombut not an entrance to said dwellings. t

To this end the invention consists in the formation of transverseopenings the full width of the screen centrally in the body and at thetop at the meeting-ends of an upper and lower section of said screen thesaid openings being formed by the peculiar formation of the angles inthe meeting-ends of said secother insects from dwelltions so as toprovide an exit for the insects as Well as to turn them back in theircourse upon the screen after being excluded and prevent their crawlingback through the passages or openings again vinto the room.

In the accompanying drawings to which reference is made and which fullyillustrate my invention Figure 1, is an outside elevation of my improvedscreen as appliedA to a window sash or frame, and Fig. 2, is a centralvertical section.

Referring by letter to the accompanying drawings, A, designates thewindow or door frame and B, the netting or wire screen applied theretowith its body standing in a vertical plane. Said netting must be made ofwire. At the center of the screenor the point.- where the upper andlower sections meet is a transverse opening C, extending throughout thewidth of the screen outl through which the insects make their exit.lGreat advantagesare thus derived from the peculiar formation andarrangement of the angles inv the upper and lower sections of the screenby which this opening as well as another above it is formed for the exitof the [iies or other insects where the same are prevented/fromeffecting an entrance back again into the dwelling. Another opening D,similar tothe one just referred to is formed at the top of the screenfor a similar purpose t. c. for the exit of the insects. The angles madein the upper and lower sections of the screen by which these openingsare formed, will now be fully described.

Secured transversely to the top and under side of the window or doorframe A, is a strip of netting or wire-gauze E, extending the wholewidthof the screen and inclined at an angle of about forty-tive degrees, andwhichuis separate and disconnected from the upper e/nd of the uppersection of the screen and constitutes one side of the opening D. Theother or opposite side of the opening D is formed by the upper end ofthe upper section of the screen which very slightly curves at the pointwhere it is bent over outwardly or toward the outer surface of thescreen, and which describes an acute angle. The lower end of this uppersection of the screen is slightly curved inwardly, as at e, and bentupon itself atf, forming an acute angle. The point where bent lies in anopposite direction to the apex of the angle of the upper end ofthe upperscreen section and constitutes one, or the upper side of the inclinedopening C. The upper or meeting end of the lower screen is also veryslightly curved from the point where it is bent over and describesanother acute angle the apex of which lies in the same direction orplane as that of theV apex of the upper end of the upper section of thescreen and constitutes the other or opposite side of the opening C,providing an inclined opening and an indirect passage.

By such construction of screen as above described the insects within thedwelling which alight upon the inner side of the screen sections, asthey crawl upward will nd a free exit through the openings C and D,`andwill 4pass directly through the same from the and away from the openingsas it is impossible for them to eect an entrance into the inside of thehouse and through the openings in consequence of the peculiarconstruction or formation of the angles forming the openings in the topand body of the screen sections for preventing the return of the insectsthrough said openings.

Having thus described myinvention, what I claim as new, and desire tosecure by Letters Patent, is-

A iy screen comprising three parts the upper section having its upperend bent upon itself leaving an inclined portion terminating in aVertical depending flange the lower MARY HALL BLAISDELL.

Witnesses:

GEORGE W. CRooKE'rT, S. A. BLAISDELL.

